That's when you need to look back, and not just focus on the most popular complained-about things, but also look at the qualitative feedback you're getting, and they to synthesize commonalities between different lines of feedback. Like another commenter said, sometimes feedback will help you reach a local maximum, but you need to infer /why/ complaints come in the first place, now just what people are complaining about, to know where to go next. If you have so many complaints and there's no clear direction, either you're at the nitpicking phase, or there are larger problems that you haven't identified yet.

If your current tagging system isn't helping you, flip the axis on which you're tagging to see if new patterns emerge. (area of complain on your product, versus types of tasks users are trying to achieve, for example.)